lctl-list_param(8)

LCTL-LIST_PARAM(8)

Lustre Configuration Utilities

LCTL-LIST_PARAM(8)

NAME

lctl-list_param - list configuration parameter names

DESCRIPTION

List the Lustre or LNet parameter name(s) matching param_search. The parameter name(s) may contain wildcards using glob(3) pathname patterns.

OPTIONS

The various options supported by lctllist_param are listed and explained below:

-b, --dshbak: Aggregate parameters with wildcards whenever a device number appears in the parameter name. By default --merge is enabled with this option to merge the simplified names. Specify --no-merge if you want the parameter names with wildcards but do not want them to be merged.
-c, --color=auto|always|never: Use one of auto|always|never as the rule of when to apply color. The default is auto which will display color only when the output is a terminal.
-D, --dir-only: Only list directories.
-F, --classify: Append '/', '@' or '=' for dirs, symlinks and writeable files, respectively.
-l, --links: Follow symlinks while searching for parameters. (enabled by default)
-L, --no-links: Do not follow symlinks while searching for parameters.
-m, --merge: Merge all parameters that have the same name such that only one will be shown. Enabled by default.
-M, --no-merge: Do not merge parameters. All parameters will be shown, regardless if they are have the same name or not. Duplicate parameters will be printed in yellow.
-o, --module: Include modules params in the parameter search path, meaning that matching module parameters will be shown along side with Lustre parameters.
-p, --path: Print the parameter path instead of the parameter name.
-r, --readable: Print only parameters that have read permission. Can be used with [-w|--writable] to print parameters that are both readable and writable.
-R, --recursive: Recursively list all parameters under the specified parameter search string. If param_search is unspecified, all the parameters will be shown.
-t, --tunable: Print only tunable parameters. This avoids printing directories and all parameters containing any of the following:
console|debug_|fail_|force|import|nis|panic_|srpc_sepol|stats|target_obd
-w, --writable: Print only parameters that have write permission. Can be used with [-r|--readable] to print parameters that are both readable and writable.

BASH COMPLETION

This command supports bash-completion(1) for tab completion of parameter names available on the local node, with suitable shell and package installation. This can greatly simplify finding which parameters are available, instead of running lctl-list_param(8) repeatedly. To list long options (more descriptive and easily understood) type '--TAB', and to list short options type '-TAB'.

EXAMPLES

Use wildcards to obtain all matching parameters:

# lctl list_param ost.*
ost.OSS
ost.num_refs

Show the file type with -F, this can be useful in combination with grep to find certain types of parameters:

# lctl list_param -F ost.* debug
ost.OSS/
ost.num_refs
debug=

Since there are multiple location that hold paramters, use -p to get the full filepath for more efficient use by external mornitoring tools:

# lctl list_param -p ost.*
/sys/fs/lustre/ost/OSS
/sys/fs/lustre/ost/num_refs

Search recursively through the directory tree with -R to get the full list of both directories and parameters in the tree:

# lctl list_param -R mdt
mdt
mdt.lustre-MDT0000
mdt.lustre-MDT0000.capa
mdt.lustre-MDT0000.capa_count
mdt.lustre-MDT0000.capa_key_timeout
mdt.lustre-MDT0000.capa_timeout
mdt.lustre-MDT0000.commit_on_sharing
mdt.lustre-MDT0000.evict_client
...

To avoid following symlinks which can lead to duplicate output use --no-links. Note that mgs.MGS.osd is a symlink to ../../ost-ldiskfs/lustre-MDT0000:

# lctl list_param -L -R mgs.MGS
...
mgs.MGS.mgs.timeouts
mgs.MGS.mntdev
mgs.MGS.num_exports
mgs.MGS.uuid
mgs.MGS.filesystems
mgs.MGS.gss
...

Compare this to the same command with --links enabled:

# lctl list_param -l -R mgs.MGS
...
mgs.MGS.mgs.timeouts
mgs.MGS.mntdev
mgs.MGS.num_exports
mgs.MGS.osd
mgs.MGS.osd.auto_scrub
...
mgs.MGS.osd.quota_slave_md.root_prj_enable
mgs.MGS.osd.quota_slave_md.timeout
mgs.MGS.uuid
mgs.MGS.filesystems
mgs.MGS.gss
...

To get a full list of tunable parameters on the filesystem combine -t with -wr:

# lctl list_param -R -L -t -wr ost.OSS.ost_seq
ost.OSS.ost_seq.high_priority_ratio
ost.OSS.ost_seq.threads_max
ost.OSS.ost_seq.threads_min
ost.OSS.ost_seq.nrs_crrn_quantum
ost.OSS.ost_seq.nrs_delay_max
ost.OSS.ost_seq.nrs_delay_min
ost.OSS.ost_seq.nrs_delay_pct
ost.OSS.ost_seq.nrs_policies
ost.OSS.ost_seq.nrs_tbf_rule
ost.OSS.ost_seq.req_buffer_history_max
ost.OSS.ost_seq.req_buffers_max

Using --merge will collapse copies of the same parameter if they have the exact same name. Multiple copies are often caused by symlinks pointing to the same directory that has already been searched. To show all parameters:

# lctl list_param -R --no-merge osp.lustre-OST0000-osc-MDT0000
osp.lustre-OST0000-osc-MDT0000
osp.lustre-OST0000-osc-MDT0000 <- symlink
osp.lustre-OST0000-osc-MDT0000.active
osp.lustre-OST0000-osc-MDT0000.active
osp.lustre-OST0000-osc-MDT0000.blocksize
osp.lustre-OST0000-osc-MDT0000.blocksize
...

# lctl list_param -R --merge osp.lustre-OST0000-osc-MDT0000
osp.lustre-OST0000-osc-MDT0000
osp.lustre-OST0000-osc-MDT0000.active
osp.lustre-OST0000-osc-MDT0000.blocksize
osp.lustre-OST0000-osc-MDT0000.create_count
...

Use --dshbak will collapse multiple OSTs and MDTs so params are easier to read:

# lctl list_param -R osp.*
osp.lustre-OST0000-osc-MDT0000.active
osp.lustre-OST0000-osc-MDT0000.blocksize
osp.lustre-OST0000-osc-MDT0000.create_count
osp.lustre-OST0000-osc-MDT0000.destroys_in_flight
...
osp.lustre-OST0001-osc-MDT0000.active
osp.lustre-OST0001-osc-MDT0000.blocksize
osp.lustre-OST0001-osc-MDT0000.create_count
osp.lustre-OST0001-osc-MDT0000.destroys_in_flight
...

# lctl list_param -R --dshbak osp.*
osp.lustre-OST*-osc-MDT*.active
osp.lustre-OST*-osc-MDT*.blocksize
osp.lustre-OST*-osc-MDT*.create_count
osp.lustre-OST*-osc-MDT*.destroys_in_flight
...

AVAILABILITY

lctl list_param is part of the lustre(7) filesystem package since release 1.7.0